Automatic train control.



H. 1. MATSQN.

AUT'OMYATICTRAIN CONTROL.

APPLICATIQN F ILED JUNE 20. i916.

Patented Apr. 8,1919.

13 sHEzTs-sHEET 1.

H. I. MATSON. AUTOMATIC TaAmnomnoL.

.PlPLICATdON FILED IUNE'ZO, 1916.

Patented Apr. 8,1919

13 $HEETS--SHEET 2.

H. l. MATSON. AUTOMATIC TRAIN common APPLICATION'HLED nmgzu. 1. 16.-

Paten ted Apr. 8, 1919.

13 SHEETS-"SHE T 3- 9mm M m a I, a r/ Iii/{0215010 H. l. MAISON. AUTOMATlC TRAIN CONTROL v APPLICATDN FILED HIRE 20| \96- Patented Apr. 8,1919.

13 SHEETS-SHEET 4.

I H. LMATSON AUTOMATIC TRAIN CONIROL.

Patented Apr. 8, 1919 13 SHEETS-SHEET 5- iumrs APPLICATON HLRD JUNE 20 [916.

ammo; I

H. l. MATSON.

AUTOMAHB TRAIN CONTROL.

APPLICATlON-EILED JUNE20. me,

Patented Apr. 8, 1919.

13 SHEETS-SHEET 6- fzzmzz m Ta. 1; MATSON. AUTO MATH TRAIN CONTROL. AFPLIQAIIQN FILED JUNE 20- 1,9!6.

Patented, Apr. 8, 1919.

I 13 SHEETS-SHEET 7- H. i. MAISON.

AUTOMATIC TRAIN CONTROL. APPLICATION FILED mm: 20, was.

Patented Apr. 8,1919

I wiwaooeo H. I. MATSON. AUTOMATIC TRAIN CONTROL. APRLICATIGN FILED JUNL 'Qit Patented Apr. 8., 1919.

13 SHEETSSHEET 9.

lwomwliop 1 H. I. MATSUN.

IAUTO'MATIC TRAIN CONTROL.

,APPu'cATmN FILED JUNE 20. me.

Patented Apr. 8, 1919.

l3 SHEETS-SHEET 0- filljal'ajon uni a I P hE y H. p. MATSQN. AUTOMATIC TRAIN C ONTROL'. APPLICATIQK LED 1N5 20, 191 6- v Patented Apr. 8, 1919. 13 SHEETS- 'SBEET l I.

H. l. MATSON, AUTOMATIC TRAIN OQNTRQL. APPLICATION man mi 29! may Patented Apr. 8,1919.

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mm/MM M51507;

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To all wkom' may some;

Be it, known the; i, HENRKI. M i'rsou, e eitizenef time United ewes; resiaiiiig at eetorie, in" the eouiifny of Clotsop State oi Oregon. have invented new aml useful impxovemenis'in Automatic Twin floiiiwols.

of Whioli the "followingis o. specification.

This invention relates to an automeiic lzreizn stop system and. has for its primary 1 control (levies is manually released.

An object. of the invention is to provifie a system cooperating with out not interfering with the em brake apparatus under clear conditions. but so designed as to make the control of vilie brake apparatus away Irom the engineer when tbhe engineer does not observe a. caution or, e. dangei signal.

Besides the. above my invention is distinguished in the following eliei'ao'teristicsz The eppamtuswvill ?zUi-( iaticelly apply the train brakes if for any meson engineer fails to observe caution 02* (longer sigr mils; sowiesignecl that the failure or displacement of an essential part will insure appl' nation of the brakes; so oonetructeii to prevent release of brakes ai tev an auto matic application has been made until enough time has elapsed as to reduce the speed of the train; trains may pass signals in. caution 01...(lil11gfil position. without an automatic application being made provided signals are observed; when, obviated will some a. sewice application aml ii the device is not released after a pre(lete 1'niine l inierval to museum emergexiov application; will.

"moi interferewvitir the a. mlicalion of lJZHlICS.

r by engineers brake valve but after an enfoifo mine-a tlangefliloelt matic agplimtion has been imicle, brakes cannot be released. with 'engineers lvieke valve until automatic control device is firs; moved. to normal position;apparatus will not :mtomaticelly-ife. seg 1e evstem can only be YG1Tl6YB6ll11 3P i a verjwliort ieng'rh Oi time such:

lie a-pix1wit11s will be under-control of engineer at all itimee we VldCil lie properly observes the signals.

figieoifieetien of Letters mom.

I Awlioetion fiieai Ilusae 2Q, 1916. Serial No. 1%,?84

' train line.

lieu it" is necessary Patented Apia e. e319;

The invention will be better understood from. the following demiied description taken in connection with the accompanying drawings wherein a. preferred embocliment is ilius'rui ed and the fezi tures of novelty including all the above mentioned and various ike will. be hereinafter pointed out iii the i 'g'goended claims.

ii; the elrewi-n s:

Figiuel a iiiagramma-tio view oi the encive- System.

2 is a somewhat similar vieW with the pirate in section.- I

Fig. 3 is a cliagmnmmtieview looking from above,

e is 2-1 sectional view-oli'the control vmve.

Fig. 5 is a on line Fig. (l is a view similar to Fig. l showing the slide valve in service position.

Fig. 7 a partial sectional view of the control valve.

Fig. S is a. view similar to Fig. in showing the slide valve in emergency position.

cross sectional view of Fig. 4%

the rotary valve moved to bleed valve re charging position.

1.? is ii View 51mm to Fig. 15 show im the rotary valve moved. to a position to whose the apparatus.

Fig. 18 is sectional View flirough *he air motor controiling' the exhaust clevice of the is e partial sectional View of the exhaust device. I i

)P is e seetionel view on line 2G-20 on Fig. y

Fri. view similar to Fig. iSWitii the moveii. i0 eaiise a. service applies.

tion of the iorelaes. I V

Fig. is e View ofe portion of the ex electromechanical devices.

the parts in service 'posie the parts in position topass air from the train line to chamber 57. I I

Fig. 24 1s a view similar to'F1g.--18 with the parts in anemergency position.

Fig. 25 is a horizontal sectional view of the exhaust device in an emergency position.

Fig. 26 is a sectional view through the air motor or the cut out valve; V

Fig. 27 is a sectional view of the cut'out valve.

Fig. 28 is a view similar to Fig. 26 with the parts in a positionto close the'cut out valve. I

Fig. 29 is a sectional view of the cut out valve.

Fig. 30 is a diagrammatic view of the electro-mechanical device.

Figs. 31 and 32 are other views of the Fig. 33 is a view, partlyin'section, o trip valve; Y Figs. 34, 35 and- 36 are diagrammatic views of the three positions of the slide valve; v Fig. 37 is a diagrammatic view of my invention showing the rotary valve in normal position. i For convenience of description and clearness of presentation I will describe my invention in the specific embodiment of the the apparatus in the drawings, but wish it understoodat the start that although I men= tion all the details of mechanism and operation, l ado not intend to limit the; invention thereto as in many respects it broadly --new-. andthe range or, mechanical I embodiments is correspondingly large. 11*

Briefly stating, the invention consists of:

An automatic control reservoir, in which the air is stored that operates the apparatus, receiving its air supply at a reduced pressure from the train line between the engineers brake valve and the cut-out cock.

An automatic control valve which consists of a cylindrical casing containing apiston that divides the easing into an auxil iary and a main compartment, the communication' between the compartments being establishedthrough a small groove and this communicatioii is destroyed upon movement of'said piston from normalposition. The main compartment of the automatic controlvalve extends at a smaller diameter to form a seat for a slide valve carried bythe piston and controlling the operation of the various elements. v j A rotary valve carried by one side of the casing by means of which theautomatic con- 'trol valvemay be manually controlled for preventing an automatic application when the trip valve is opened for a short interval, 1 also to effect a release of the apparatus or system after it starts operating by directing a flow of air at an increased pressure into the main compartment of the control valve. The main reservoir cut-out valve which consists of a plug valve that is automati- 7o cally turned to stop the flow of air from the main reservoir of the brake apparatus through the engineers brake valve while the system is in operation, being automatically returned to open position when the control device is released.

The brake pipe discharge valve which opens the brake pipe to the atmosphere allowin a predetermined amount of air to escape. rom the brake pipe in a service up plication, thenstopping'this flow after the required reduction has been made in the brake pipe pressure and if the system .is' not returned tojnorm'alposition or release I position to open a discharge port for allow ing the proper-amount of air to escape from the train line for housing an emergency application'of the brakes. a

The retarding, reservoir which is a small reservoir used to increase the volume of the main compartment offthe control valve. The retarding IGSGIVOIIJS 1n communicamovement of the slide valve, but the communication is again opened upon theslide valve reaching-an intermediate position and thus the sliding action of the slide valve is retarded when passing from the service position to anemergency position.

A trip' valve arranged to be opened under danger conditions for bleeding air fromthe' main compartment for allowing the piston and Withit the slide valve to move.

The track apparatus by means of which the trip valve will he opened under danger conditions.

Broadly stating. the operation of the foregoil'ig apparatus is as follows:

, The trip valve is opened by the track ap- 11o paratus which causes the pressure in the main compartment to be reduced so that the piston and slide valve may move into a position to allow air from an air reservoir to pass to the valves for cutting off connnunino cation between the engineers brake valve and Ithetrain line to a degree to cause an emergency application of the brakes.

Referring tothe drawlngs, the numeral 1 designates the casing, the interior of which is dividedinto a main compartment 2 and an auxillary compartment 3 by means ofax pisthis by-pass'is vice 9.

incense ton 4. The compartment 3 communicates directly with an air reservoir 5 by means of a pipe 6, while the main compartment 2 communicatcs with the reservoir by means of a pipe 7, the passage within which being ob- Sl'iIUCted at certain times in a manner to be described later. When the )iston is in nor-- mal position as'illustrated in Fig. 4:, a by-.

pass 8 establishes communication between the compartments and communicating with the pressure rel eving de Formed within the inain compartment 2 is a valve seat 10 having a pair offeed ports l1 and 12 communicating with each other and vwith the pipe 7; an exhaust port-13,outlets I 16, an exit17, a passage 18 and a 14, and

. drain opening 19. Communicating with the;

outlet 14 is a -20 depression 20 in the valveseat and the outlet 14 also communicates with one end of a pipe 21 that branches at the point 22 so, as to communicate with the main cylinder. or application cylinder 23 of an air motor' 24 and with the main or application cylinder 25 of anair motor 26. The outlet 1!) communicates with one end of a pipe 27 the other end of which communicates with the cylinder 23. A pipe 28 connects the outlet 16 with the auxiliary orrelease cylinders 29 and 30 of the air motors.

I Referringto Figs. 26 to 29 inclusive of the drawings, it will be seen that the pistons 31 and 32 -sliding in the cylinders of the motor 26 are rigidly connected together by means ofa rack bar 33 that cotiperates with a segmental gear-34 secured to the stem 35 of the plug 36movable in the casing37 of the valve 38. This valve 38 is arranged in theinaiii reserto be described later.

voir pipe between the enginecfis brake valve the cylinder 30, the associated piston will be moved in a position to reopen the valve and this action is automatically controlled by means of a device actuated by the .piston t over the valve seat.

Referrin to Figs. 18 to 25 inclusive oi -the drawings, t 1e numerals 42 and 43 designate a pair of pistons, the former working in the cylinder 23, the latter in the cylinder 29 and both ri gidl y connected together by means of a rack bar 44 cotiperating with a segmental gear 45 secured to the stem. 46 of a valve 47 That end of the rack bar connected to the/ piston-l2is recessed as indicated'at 48 sons to receive tliehe'aded end 49 of the stem 50 of an auxiliary piston 51, also slidably mounted in the cylinder 23. The piston 51 is adapted ton'iove toward the piston 42 and for preventing disengagement between these pistons, I arrange-upon the adjacent face of the piston 42 a plate 52. The pipe 270011111111!- cates with the cylinder 23 insuch a manner that thea-ir. passing thei'ethrough will onlyact upon one face of the pistoni51, whereas a branch of pipe 21 is so arranged. in the cylinder 23 that air passing, therefrom will wedge in between the pistons 51 and i2 with the result that the piston will be 'forced in opposite directions. By this arrangement it will seen that the movement of the piston Ellis limited in one direction by means of the cap 53 while the movement of'the piston- 42 is limited in the opposite direction by ineans of the engagement between the plate 52 and the head 49 of the stem 50. "The purpose of this action is to prevent a complete movement of the valve 47. In 'a manner to be described. 4

later, air is prevented from entering through the pipe 21 while air is'being forced through the pipe 27 withthe result that the piston 51 is forced rigid connection takes place between the pistonsboth will move as a unit in a direction to fully move the valve 47. Upon air entertoward the piston. 42 and when a i ing the cylinder-29 behind the piston 43, the

valveand piston 42 and to normal position.

An exhaust device 54 is provided for .the purpose of exhausting air from the train 51 may be returned me under caution or danger conditions.

This exhaust device consists of a casing 55 having an upper chamber 56 and a lower chamber 57 that ommunicates with the atmospherc through a slot58 in the casing. Mounted in the chambers is a double disk valve 59, the disks 61 and 60. of which are of different diameters. The disk .60, the smaller of the two is slidably mounted in the chamber 56 and carries a stem 62 nor-- mally bearing upon the diskiil that engages a seat 63 in the chamber 57. From this arrangement-it, will be seen that when equal ressures act u on the dislt'both disks will c moved vertically owing to the greater iis area of the disk. 61. The .upper portion of.

the piston 60 is adapted to be thrown into communication with the train line pressure by means of a passage 68, the continuity of which being controlled by the groove 65 in a the plug 66 of the valve 47 'VVhen the plug 66 is in normal position air is free to pass from the train. line in which the valve casing 67 is arranged to the chamber 56 directly above the piston 60 with the result that the downward pressure seated. I 1

The vpassage 68. the continuity of which being controlled by the heretofore menholds the valve 61 movement of the plug 66which takes place instantly reducing the pressure of the train line to a degree to cause an emergency applie so i .tioned groove 65 or a second similar .groove 69 in'the plug valve is adapted to allow air to ass from the train line into the chamber 57 elow the disk 61 and as the pressures are equalinthe chambers, the two disks will be' moved upwardly for allowing enough air to escape through the slot 58 to compensate for the difference of areas of the disks. At this point'I wish to call attention to the fact that when the chamber 57 is thrown into com munication with the train line, as shown in Fig. 23, the plug 66 assumes a position to cut ofi communication between the chamber 56 and the train line and. thus a certain amount of air is trapped above the piston 60 atoriginal pressure; By this arrangement it will be seen that the difierent areas of the disk will allow several pounds of air to escape from the train line for causing serv-- ice application of the brakes. Further after both pistons 51 and 42 have moved as a unit will cause a. bore 70 in the plug66 to; establish through a bypath 68 direct communication between tlie train line and the atm'osphere,as shown in Fig. 25, for

cation of the brakes. The valve casing of the, plug 66 is provided with a bleed port 71 adapted to com 4 manually operated by the engineer.

handle is capable of assuming three positions and for the purpose of'holdingthe handle in its three positions, I provide a connected with the air brake apparatus, as shown in Flgs. 1 and 3, so as to communicate municate with the passage 68, as shown in Fig. 20, through the passage 69 in the plug when the plug is returned to normal position .for bleeding to the atmosphere the remainpressure that exists in the -cham-' ing air ber 57. a I I Mounted upon the side of'the casing 1 is a casing 72 of a rotary valve, the rotary plug 73. of which bein connected to a handle 74 arranged exterior y of the casing so as t plbe rack' 7 5 cooperating with a spring pressed dog 76 mounted in the handle. At, this point I wish to call attention to the fact that a chamber 7 7 is formed between the plug 7 3 l and the rear wall of the casing, and communicating with this chamber is a pipe 7 8 with the main reservoir 41. Besides holding the plug 7 3 properly seated, this air sup:

. ply in the chamber 7 7 is allowed to enterthe main compartment 2 for returning the is- .ton 4 to normal position when the handle 74 has moved to a predetermined position.

The stem 79 of the piston 4 is guided in its movements by means of a spider 80 engaging the wall of the main compartment. Connected to the stem 79 is a slide valve 81 vieldably held againstthe seat 10 by means of a leaf spring 82 interposed between the *stem 79 and the slide valve. "The slide valve is formed with'an opening 83 continuously in alinement with the passage 18 in the seat when the-slide valve is in normal position with the result that air pressure in the main compartment may pass through theopening 83 into the passage 18 from whence the airpassesto an auxiliary reservoir 84 by means of a-pipe 85, thus it will be seen that in a normal position of the slidevalve, equal a pressure will exist in the air reservoir 5, main and auxiliary compartments 2 and 3, and auxiliary reservoir 84:. In the initial movementof the slide valve communication is immediately cut 01f between the auxiliary reservoir 84; and the compartment 2 by the opening 83 moving out of alinement with the passage 18, the latterbeing closed by the face of the slide valve. Thus it will be seen that a reduction of air in the compartment 2 will not affect the pressure in the auxiliary air reservoir 84, in the initial movement of the slide valve which movement would come spond to a service application of thebrakes.

This movement would carry the slide valve one half of its travel and any furthermovement beyond this would cause the passage 18 to be uncovered with the result that the excess air pressure in the reservoir 84 would pass into the compartment 2 for increasing '86 when the handle 74 is in any position but normal corresponding in this case to a vertical position. The passage 86 communicates with the pipe 88 passing to'a bleed valve 89, the purpose of which is to bleed the maincompartment 2 of air pressure for allowing the excessair pressure in the compartment 3 to move'the piston and slide valve in a position to accomplishfcertain results hereinafter mentioned."

The slide valve is provided with a T shaped groove 90, one limb 191"of which passes through one end 92 of the slide valve.

another limb communicating when the slide valve is m normal positionwith the 'feed port 12, and the remaining limb 94c communicating with the outlet 16 when the slide valve ism normal position. From this arrangement it will be seen that when the slide 'valve is in normal positio'm'the air pressure 1n the'air reservoir? s free to pass through the feed port 12 to the compartment 2 through'the limbs 91 and 93 oftlie T shaped groove 90 in the slide valve, and simultaneously with this action air passes from the feed port 12 through the remaining limb 94 1 This grmwe 95 is arrange/(i to eeimamnimee 'withthe dram meaning 19 when the Ade g'i'eeve $5 moves mic eommumeatlen 2 1th valve has cmve ied one-ha1f of: Lee distance with the'result that the air gness re in the compartmenbimay (1min m the a 121051 lere through the groove 95, Grain ape 'ntn a. passage 9'? eommunicatieg with; eempa'rtment 2 at one end and filth the I phei'e at the other enfL, a, partial m which 15 150mm. by a greeve 98 in pin vflve em? thisg'mm'e 9S errengefi in aent with v-he passage 9'? when the hamhe E1: is in a 110mm Venice-L pesitiem 'Wl'um. the

the epening 19, the lide velvehes traveled. a distance great eneugh "m sever 'she with 1'? with the result abet further bieeaimg-ek m1 from i; ve compafivn'zeht through the ed valve 89 is preveuized, 21 116. few-Sahel Meedmg of (he air takes place very siew'fiy tin grams 9%, opening; 19 ix groom and (bus retarding: fl IifKiL-li ment e? the slicie valve.

When ihe slide mive is me'ving {rem e paint of rec-3t to e geeitien Where eemmzmi catien takes place between the gmeve 2121i opening 19, the applicetien eyiiniiet'e ""3 2.3165 25 of the air motors are thre'wm in. mmmuei cation with the reeer'veir- 5 fin pass 99 in. the slide valve esiebi municetien bet-Ween. the feed pert outlet In this posit-ion 0i the siicle 131E eiz' passes from izhe reset-veil throug be due pi gae 2:1 3 whenm, tars Hie cylinder beiwe "m and 51, @1115. also {M10 against the PiSiiOn 31 neousiy with this eetien air is reie eed. fmm fl'me eyfinders and 30 by means of a third groe've meving; into a peeitim :ze es A lish cammimicatioe. bee een and exhausi'. port 13 that cmnmuni the e'unesphere. The gme've 1&8 with an pm'tion. 101 fez He 1" t nowing the interime5 *1 r" 25 Em- 0 communieaiim; thxj'eugzh the exhaner port; vzdve is in warren} peeitien Zeb 15 and entiet 1 k and a sien :20.

me tinere'i'z'a. fhmulm yum-192m}; e HMYiCH app'iieetien of thebrekes,

.Upotn aha slide valve reaching its final posi tion, ,ihe outlet 15 is thrown ineemmunicaiien wizh the fee port 12 which causes air 3n the main reservoir 5 t0 pass threugh pere 3.2 m the pipefz'i passing into the eyiimier 23 so as to only act upen the piston nrmal. position se that ihe passage 10 in ,the glug; 73 will estzxbhsh eqmmumeatlon be tween the chamber 5?? and hat-portion 195 e? the passage 86 ext-ending toward the pipe that eemleets .te the bleed valve 89, The purpese of this arrangement is to recharge thepipe 88 and, valve 89 from the main reser-.

voir after the bleed valve has -been ep'ened 5116 danger conditions eye over, when the plug hancde M- is threwn t0 the position justmentionfi (see Fig. 16), the-eomparimem i3 fira'rewn'fln direet eenununicution with the atmespiaere through. a paseege 3.05 that cenueets a? ene end with the compartment h other eni m'mnged in communica- Lien with die gmove 98, the air passing from the eempal'tment through the passage 1 36, g mme 98 and a pertien of the e'seege 9'3.

The advantage oiihis mesa-action is that the hanfile cannot be kept in this abnormal pm; we beyomi' a predetemuned n'xterml es compartment 2 1s drained, dlrectly to e atmeephere. After the pipe 88- and vehe 8%.? has ieen ehergefi w'mem reservmr prese handl 1e thrown an the opposlte its my; 13 gesltlme, Flaggl'a', ee as to 8 into e pesflzien to estabneh we can wig; of the passage 8.6 so that flze excess fl11p'if8S$1ll8'1R the pipe 88' and @lve may into the cemg-artment 2 resmre qhe mechanism. When the E8 t'hrewn into this latter abnorma m the wessege 106 is fihrew'n in com- Hem wieh the pembien 1050f the pee y 3 means ef the greoye 87 int-he plug $3,,im-meby ehewmg W10 amiss for the ab: pressure in eemperfiment Q, ee pess therefrom as cfieariy snmm m 139;. 17. 4

The Meet: vah efi 2215 particular mstance eensiste efe. casing 107 having a mxbie waive seat L208 em 16 9, the Eat-tel begreater diameter than the farmer. V aiming with-the cieueae valve seats 108 am} M9 are fisk valves 13.9 and 721i eennect ed; by a; syie? 112, the va'ive stem 113 passes;

' .hreegh' a ping 11% manna? in the easing 1G"? seed is eetefi. upon 3 means of bee arm fife liever 115 piveted ta e'suigteble sil'ppeyt as izgdieaizeci at 116. The remaining arm '11"! ef the iever 1e eexmemeci tee plunger 118 that is under the influence of a solenoid 119 fact that the disk valves 110 and 111 are so 4 tacts 123 and 124 and a pair of movable con ated in any suitable manner such as when the arran' ed that air passing throughthe pipe 88 wi I act upon the disk valves 110 and 111 in such a manner that one will tend to prevent movement of the other but ow'in greater diameter of one of the dis s, the valve will be unseated, but may be again seated with very little opposition. Gommunicating with the valve seat 108 is a bleed port 120.

The-solenoid 119 is arranged in the nor-.

mallyclosed circuit 121' including a source of current 122 such as the storage battery. The continuity of this circuit 121 is controlled by means of a pair of stationary contacts 125 and 126. Each of the contacts 125 and 126 is mounted upon the short arm 127 of a lever 128 which is insulated and fulcrumed to a stationary support as indicated at 129. This lever 128 terminates in a shoe 130 arranged to enga'geone of a pair of contact rails 131 and 132. The contact rails 131 and 132 are arranged to opposite sides of the main rails 133 and 134 of the trackway and the levers 128 are positioned upon the train accordingly. Thecontact rails 131 and are connected together by means of a con ductor 135 includlng a source of current 136. Under clear conditions this conductor 135 15 continuous, but under danger conditions the continuity of the conductor 135 is destroyed by means of opening the switch 137, oper semaphore blade oes to'danger position or by any other s 'uita le mechanism.

The operation of the device is as follows assuming that the block being approached has its signal at danger position When proceeding under clear conditions, the solenoid 119 is energized by the battery 122, thus holding the valve 89 closed,-but immediatelythe shoe 130 engages at the "contact rails 131 and 132, the circuit 121 is broken at the contacts 123,124, 125 and 126, as the rails 131 and 132 are unelectrilled, due to the breaking of the conductor 135 by the switch 137, the solenoid 119 will be deiinergized with the result that the pressure in the pipe 88 will move the disk valves in a direction to uncover the bleed port 120. hen this action takes place, the air pres- "sure in the compartment 2 is reduced and a the greater pressure in the compartment 3 causes the piston 4 to'travel in a direction to move the slide valve over its seat. In the initial movement of the slide valve communication is cut 011 between the compartment 2' and the auxiliary "reservoir 84, thus keeping pressure in the reservoir 84 atnormail. The travel of the slide valve continues until the compartment 2 is thrown in to the I communication with the atmosphere proand groove 98; simultaneously with this action. the feed port 11 from the reservoir 5 is thrown into communication with the outlet 14 by means of the by-pass 99. Ai r pressure passes directly through the pipes 7 v and 21 into the application cylinders so as to act upon pistons 51 and 42 of the air motor. When the slide valve is in this latter position the cylinders 29 and 30 are thrown into communication with the atmos phere through the pipe 28 to the exhaust "port 13 through groove 100. '1hereciprocastory movement of the rack bars 33 and 44 cause the valve 37 to be closed for cutting ofl communication between the main reservoir 41 and the engmeers brake valve 40 midthe plug 66 of the valve 47 moves to! an intermediate position so as to trap a quantity of train line air pressure above the piston 60 and allowing train line pres sure to act upon thedisk valve 61 for unseating the same, and allowing enough air 'to escape from the, train line to the atmosphere to compensate for the difference of I areas of the disk valves ()0 and 61. This action causes the service application of the train brake.

If, after a predetermined interval the engineer has not manipulated the handle 74 for recharging the compartment 2 from a the main reservoir 41 by way of pipe 78 and passage 1.04 and valve disk, the slide valvewill continue its movement and even tually causing an emergency application of the brake by directing air through the pipe 27 so as to act only upon the piston 51 and movingboth pistons in the same direction to-the 'lif mit of their travel. This actiongives the complete movement to the plug (16 so as to bring the bore 70 into direct communication with" the atmosphere and the train line for instantly reducing the pressure to a degree to cause an emergency ap plication of the brakes.

The air from the reservoir5 passes through thepipe 27 in a manner illustrated in Fig; i

36 of the drawings wherein it willbe seen i that the by-pass 99 directly connects the i outlet'lfi with the feed port 12 that communicates with the reservoir 5. At this point I wish to call attention to the fact that when air passes through the pipe 21 it acts differentially upon the pistons 42 and, 51 so that "the head portion of the stem 50 will limit the movement of the piston 42.

For resetting the apparatus after a service or an emergency application of the brake, the engineer moves the plug 73 by the handle to one side of its vertical position as indicated. at Fi 16 so that the air pressure in the'chamber 77 received from the main reservoir 41 by way of pipe 78 niay pass 

